Telephone system.



A. H. DYSON.

TELEPHONE SYSTEM.

APPLICATION FILED MAR. 31 1914 Patented Dec. 11, 1915 /m/e/7/0/': I A/f/ea H. Dyson.

by I

'Ar/j/ W/ esses:

UNITED STATES PATENT OFFICE.

ALFRED lDiY SON, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY,-OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

TELEPHONE SYSTEM.

Specification of Letters Patent. Patented Dec. 14, 1915.

Application filed March 31, 1314. Serial No. 828,587.

To all whom it may concern:

Be it known that I, ALFRED HARTWELL DYSON, a citizen of the United States, re-

siding at Montclair, in the county of Essex cated at a central oflice are controlled over two line wlres leading to a subscrlbers sta-- tion without the aid of a third conductor a The object of this invention is to provide means for variously controlling the switches of the system over these two line conductors." .The particular classes' of control here pro vided'for are the movement of the contacts of a switch to a desired position, the maintenance of the switch in this desired posi-f tion.

tion during the controlof'other switches and the return of the switch to its normal posi- The mechanism for accomplishing this control consists of an electromagnet whose armature actuates members mounted upon opposite sides of said armature.

These members, having been actuated upon the energization of said electromagnet, re.-

i turn to their normal position after the lapse of a predetermined interval, which interval may bevaried by the proper proportioning of the inertia and friction of the parts comprising said members.

The invention is illustrated in thefaccompanying drawings" in which Figure l is a front elevation of the mechanism for obtaining the desired time interval, and Fig. 2 is a circuit diagram showing the portion of a telephone system in which this mechanism is used.

The mechanism of Fig. 1 comprises a's'upporting bracket l, Wltll an extenslon' arm 2,

- having armature 3 pivotally mounted on the end thereof at point 4. Upon said bracket 1 is also mounted electromagnet 15, which comprises a double wound coil. The open-1 ing of contact 25'places the two windings of opened by means of projection 26, which is carried upon the extreme end of armature 3, when said armature 3 1s attracted upon the energization of e1ectromagnet-15. As con- This contact is the end of arms 5 and 5 are connecting bars i 8, 8, which carry inertia wheels 11, 11. Said inertia wheels 11,- 11" are mounted by means of a short steelshaft which turns upon a steel wire track 13, said track being held in an inclined position by supports 14 and 16. Arms, 7, 7 of the bell crank levers .are in operative relation with. the armature 3 so as to cause contacts 19 and 22 to close when said armature is attracted upon the energizationof electromagnet15. When either of arms 7, 7 are momentarily disengaged by armature 8, 'inertie wheels 11, 11 vunder the influence of gravity cause the short steel shafts 12, 12, upon which said inertia fwheels are mounted, to turn upon track 13.- The rotation of inertia wheels 11, 11' causes. members 7, 5, '8, 11, and 7 5', 8', 11 to move'to a position of rest, which is reached when arms 7, 7 again engage armature 3. The time requiredfor this operation is predetermined and may be varied by the proper proportioning of the inertia and friction of parts 7, 5, 8, 11 and 7', 5', 8, 11. In Fig. 2 are illustrated the parts described above which are designated by the numerals 15, 19 and 22. In this figure the calling subsoribers station 30 is provided with the usual transmitter and receiver and with a control-' ling device having contacts 31 arranged to open the circuit. of the line conductors 32 and 33 in the transmission of a signal. This line is connected through suitable switch contacts with the conductors of'a selector switch circuit whereinthe line conductor 32 extendsthrough one winding of relay 34 tothe live pole of central battery 35, and line. conductor extends through another winding of relay34 to the ground pole of saidbattery.

The preliminary closure of the line at the tacts 36 .and the conseouent energization of electromagnets 15 and 37. The electromagnet 15 has two coils, the upper 'coil being normally short circuited; the lower coil is energized first, causing contact to be opened, thereby placing both windings in series.

The energization of electromagnet 15 at tracts armature 3, thereby permitting the closure of contact 19. The closure of said contact establishes a locking circuit for relay 37 by way of battery, coil of relay 37, contacts 38, 19 and ground. It will be noted that the same time contact 19 is closed, contact 22 is also closed, but a predetermined number to one of the digits of the desired subscribers number. At each interruption the relay 34 releases its armatures and by the deenergization of said relay 34 the back contacts 42 of that relay complete a circuit throughfront contacts 41 of relay 37, contact 45 and the coil of primary ,stepping magnet 46 to battery. Current in this path energizes the stepping magnet 46 once for each time that the circuit is interruptec'l at subscribers station 30.

magnet 46 is of a type in which each energization and denergization of the primary magnet 46 moves a set of contact wipers in front of a group or a row of contacts; thus one energization of the primary magnet 46 places the wipers in front of one group of the contacts, two energizations and deenergizations in front of another and so on, the number of groups usually being ten. hen the relay 34 is deenergized by the interruption produced at the subscribers station 30, the circuit of electrom: gnet 15 is broken and armature 3 is returned to normal position by restoring spring 17. Contact 22 is thereby immediately opened. In order to allow its subsequent closure, said relay 34 must be energized for a period of time sufficient to allow parts 7', 5, 8 and 11 to return to'normal position as previously described. The time required for this operation is always predetermined, and may be varied by the proper proportionino of the inertia and friction of said parts. There is a brief pause at the end of the first series of interruptions produced by the circuit breaker 31 in calling-the first digit comprising the called subscribers number. Duringthis time electromagnet 15 is energized a sufficient interval to permit parts 7', 5, 8 and 11 to return to normal position, and the consequent closing of contact 22 whereby a circuit is completed through the The switch con-- trolled in its primary movement by stepping impedance coil 39, contact 22, conductor 47, contacts 49 of the secondary olf-normal set of springs, contacts 48 of the primary offnormal set of springs, which are arranged to close upon the first energization of magnet 46, and the coil of relay 50 to battery, thus actuating the relay 50. The actuation of re lay 50 completes a circuit through its front contacts 51, interrupter contacts 52 and secondary stepping magnet 53 to battery. The magnet 53 is adapted to move the contact wipers over the contacts of the group which has been picked out by the previous actuation of magnet 46, the circuit for magnet 53 being made and broken by its own contacts 52 so long as the relay 50 remains in its actuated condition. Upon the first actuation of secondary magnet 53, the wipers 54 were moved into contact with the first of the series of contacts in the particular group which had been picked out by directive actuation of primary magnet 46. These contacts are connected with trunk lines extending to other switches and as will be hereafter explained, the contacts connecting with busy trunk lines .will have a guarding potential thereonto indicate the busy condition. Considering that the first few contacts to be reached by the private wiper 54 are thus guarded by a ground potential, a circuit is completed through conductor 55, front contacts 56 of relay 37, front contacts 57 and coilof relay 50 to battery. Current in this part maintains the actuation of relay 50, which maintains the circuit through the secondary stepping magnet 53 until the private wiper 54 arrives upon a non-grounded trunk contact, whereupon the circuit in the path just described is interrupted and the relay 50 resumes its normal position, opening the circuit of the secondary stepping magnet 53 and closing its own back contacts 58, thus putting ground potential upon wiper 54 and the contact of the trunk just selected to guard this trunk against its selection by other switches. It may be stated here that the secondary off-normal contacts 45 and 49 were interrupted upon the first actuationof secondary stepping magnet 53. The next series of interruptions which are made by the controller 31 at the subscribers station in designating the second digit of the desired number similarly deenergizes the relay 34 but this time, instead of controlling the circuit of the selector switch shown in the drawing. the circuit of the next switch in the series will be controlled. Primary magnet 40 and secondary magnet 53 are not actuated because their respective circuits are broken through the opening of secondary off-normal contacts-45 and 49 as described above. As before, the electromagnet 15 will be encrgized by the first deenergizaticnof relay 34, and at each deenergization of relay 34 a circuit will be completed through the back contactsHlQ, front contacts 41 of relay 3?, cone ductor 44:, back contacts 60 of relay 50, wiper 61, conductor 62 and a magnet of the next. switch in the series. At the lapse of a pre-' fall away,.breaking the circuit for electromagnet 15. This permits the parts 7, 5, 8 and 11 to return to normal position after a predetermined interval, thereby opening con} v tact 19. As previously stated, the length of this interval may .be-varied by the proper 'proportioning or adjusting of the inertia and friction of said parts. The interruption of contact 19 breaks the locking circuit for relay 37 and permits that relay to return to normal, closing its back contacts 66. A circuit is thus established through back contacts 42 of relay 84, back contacts 66 of relay 37, primary off-normal contacts 48 and coil of relay 50 to battery. The actuation of relay 50 again brings the secondary stepping magnet 53 into--circuit which, through its pawl, continues the movement of wipers 54, 61 and 64' over the contacts until the switch has been moved to its extreme secondary-position beyond the last contact in the group. At thispoint the primary retaining pawl is tripped. permitting the switch to return to its normal position so far as its-primary movement is concerned. At the end of this primary movement, the secondaryretaining pawl istripped, permitting the switch to return to its normal position so far as the secondary movement is concerned. The interruption of contacts 56 of relay 37 removed the guard potential from private wiper 5a, and caused the release of the next/succeeding switch in the series. Even before the release ofthe switch is accomplished, parts 7 5, 8 and 11 are returned to their normal position by means of spring 17, upon the deenergiz'ation of relay l5. All'of the apparatus is then returned to its normal position and is in readiness for a second'call.

It is to be understood that the apparatus of Fig. 1 may be applied to many other types of system than that shown in Fig. 2, and that modifications may be made in the apparatus itself without departing from-the spirit or scope of this invention. 1

lVhatis claimed is:

1. Ina telephone svstem, the combination with an impulse sender, of a switch, a controlling relay for said switch under the "control of said impulse sender, and a plurality of c1rcu1t changing devices, an electromagnet for operating said devices, one of said devicesacting at a predetermined time after the last deenergization of said controlling relay to change the circuit -controlled by said relay.

2. In a telephone system, the combination with an impulse sender, of a switch, a controlling relay for said switch under the control of sald impulse sender, and a plurality of c1rcu1t changing devices, an

electromagnet for operating said devices,

said magnet being always responsive to said relay, one of said devices acting at a predetermined lapse of time after the last deenergization of said controlling relay to change the circuit controlled by said relay. 3. In a telephonesystem, the combination with an impulse mechanism, a switch at the central oflice, a pair of operating magnetstherefor, a. controlling relay for said magnets under the control of said impulse mechanism, a plurality of c1rcu1t changing devices, an electromagnet for controlling said devices, one of. said devices acting at a predetermined time after the last deenergiza tion of said controlling relay to switch the.

circuit controlled by said relay from one electromagnet to another.

I. In a telephone system, the combination with a selector switch, a set of movable contacts for said switch and a. plurality of sets of stationary contacts, an operating magnet for causing the movement of the movable contacts to various sets of stationary contacts, a relay for controlling said operating magnet, a plurality of circuit changingdevices, an electromagnet for controlling said devices, said electromagnet also being controlled by said relay, one of said switching devices being adapted to remove said operating magnet from the control of said relay at a predetermined time after the last control of said magnet by said relay.

5. Inan automatic telephone system, the combination witha selector switch, of a primary controlling magnet and a secondary controlling magnet for said switch, a. relay for controlling said primary magnet, a plurality of circuit changing devices, an electromagnet for controlling said devices for bringing the secondary magnet into action at a predetermined time after the last action of the primary magnet. 6. In an automatic telephone system, the combination with a selector switch, of a primary controlling magnet and a releasing magnet for said switch, a relay initially causing thecompletion of the circuit of the primary magnet each time it releases its armatures, and a plurality of swltching devices, an electromagnet for controlling said devices acting after a predetermined time switchin devices and an electroma net for controlling said devices which are operated between each series of impulses to change the circuit tobe controlled. 15

In Witness whereof, I hereunto subscribe my name this 28 day of March, A. D., 1914.

ALFRED DYSON.

Witnesses E. EDLER, NANON E. TUTI-IILL. 

